set crengine cache size in lua code

crereader.lua

@@ -18,6 +18,9 @@ CREReader = UniReader:new{
 function CREReader:init()
 	self:addAllCommands()
 	self:adjustCreReaderCommands()
+
+	-- initialize cache
+	cre.initCache(1024*1024*64)
 	-- we need to initialize the CRE font list
 	local fonts = Font:getFontList()
 	for _k, _v in ipairs(fonts) do